electricmanscott
Senior Member
- Location
- Boston, MA
What are the actual and real benefits of having Arc Fault Protection. Specifically in older homes what protection could one expect from replacing existing breakers with AFCI's?
The manufacturers get to sell an expensive product.Originally posted by electricmanscott:
What are the actual and real benefits of having Arc Fault Protection. Specifically in older homes what protection could one expect from replacing existing breakers with AFCI's?
I think they will be great when the combination type is available. Those haven't proven themselves yet and they are not required in older homes. If they perform as advertised, it would be the best thing since the GFCI in older homes.Specifically in older homes . . .
First question; it will comply with the codeOriginally posted by electricmanscott:
What are the actual and real benefits of having Arc Fault Protection. Specifically in older homes what protection could one expect from replacing existing breakers with AFCI's?
Very well put. What ever happened to the old lets get it right the first time additude, AFCIs, IMO cause more trouble than its worth, older homes, if required to have them in your neck of the woods, are where the problem lies. I rewired an older home but upon the wishes of the HO in his opinion and to save a buck or two insisted some of the old bedroom circuitry be left, after we came to an agreement it was left as is, well when AFCIs were installed, problem after problem, I had to rewire the bed rooms also, problem solved and extra cost to the HO.I see this an another example of redundant psychology. We place sensors on our equipment to detect imperfect product output. This is fine but we also get requests to add more sensors to back up the existing sensors in case they fail to function properly - redundancy. When I get these requests I can't help myself but to ask, how many backup sensors should we use? What if sensor #1 and #2 both fail? Should we add sensor #3, #4, #5...or would all of this be eliminated if we just repair sensor #1 in the first place?
Suppose the sensors have a 95% reliability, and a 5% change of failure. The probability that two independent sensors would both fail is 0.25%. The probability that three independent sensors would both fail is 0.0125%. The probability that four independent sensors would both fail is 0.000625%. I'd stop at two.Originally posted by bthielen:. . . how many backup sensors should we use? What if sensor #1 and #2 both fail? Should we add sensor #3, #4, #5 . . . ?
Absolutely! If (for example) you can get the failure rate down from 5% to 1%, you would be far better off, and at a much lower cost.. . . or would all of this be eliminated if we just repair sensor #1 in the first place?
Why would anyone tie neutrals together?Originally posted by allenwayne:
This might sound stupid but I`ve done that before. Lets say a house is roughed in and there is an afci circuit and a non afci circuit in same 2,3 or4 gang,If neutrals are tied together when a load is put on the afci circit it trips.
No, EGC's can be tied together; just not neutrals.What about the grounding conductors code says all grounds in a box will be tied together correct me if I am wrong. I read it but am to fuzzy to search the article. Now if the non afci`s ground is tied into a afci ground wouldn`t that trip the afci ground to neutral fault?
It's difficult to tell from here, but . . .If I am speaking out my rear (done that been there) Correct me please !!!!
I keep forgetting the difference between what they're said to do, what part of what they might do causes them to be required, and what they actually do.Correct me if I'm wrong, but I thought the current AFCIs were not designed to detect any faults on external devices, only the interior wiring?